There are known in the art a number of pharmacologically active quinazolinones which are substituted on their heterocyclic ring with a piperidinylalkyl side chain. Such compounds may be found in the following references:
U.S. Pat. Nos. 3,322,766; 3,528,982; 3,635,976; 3,812,257; 3,865,827; 4,096,144; and 4,099,002; PA1 Fr. Pat. No. 1,431,815; and PA1 J. Med. Chem., 8, 807 (1965). PA1 X is a member selected from the group consisting of ##STR2## wherein said R.sub.a is hydrogen or lower alkyl and said q is the integer 2 or 3; PA1 R is a member selected from the group consisting of hydrogen, hydroxy and lower alkyl; PA1 Alk is an alkylene chain having from 1 to 4 carbon atoms; and PA1 Q is a quinazolinyl radical, the 1-, 2-, 3- or 4-position of which is connected with the alkylene side chain, said quinazolinyl radical bearing in one or both of its 2- and 4-positions a carbonyl or thiocarbonyl group, wherein the benzene ring of said quinazolinyl radical is optionally substituted with 1 to 3 substituents each independently selected from the group consisting of halo, lower alkyl, lower alkyloxy, trifluoromethyl, nitro and cyano, and wherein the pyrimidino ring of said quinazolinyl radical may be partly or fully saturated, said pyrimidino ring being optionally substituted with 1 to 3 substituents independently selected from the group consisting of lower alkyl, aryl and aryl(lower alkyl);
The compounds of the present invention differ from the foregoing essentially by the presence of particular substituent groups on the piperidine ring of the piperidinyl-alkyl side chain.
In U.S. Pat. No. 4,035,369 there are described a series of 1-(benzazolylalkyl)-4-substituted piperidines, from which the subject compound of this invention differ essentially by the replacement of the benzazole group by a quinazoline group.